WASHINGTON – President Barack Obama said Friday he would reform and restart the military tribunals he once reviled for Guantanamo Bay detainees, jeopardizing his timetable for closing the prison by January and dismaying many supporters who suggested he was going back on campaign promises.

Now, after the detainees are given stronger legal protections — a ban on evidence obtained under cruel duress, for example — the trials of 13 defendants in nine cases will be restarted no sooner than September. Five of the 13 are charged with helping orchestrate the Sept. 11, 2001, attacks.

The rest of the 241 Guantanamo detainees will either be released, transferred to other countries, tried in civilian U.S. federal courts or, potentially, held indefinitely as prisoners of war with full Geneva Conventions rights.

"This is the best way to protect our country, while upholding our deeply held values," Obama said, announcing his decision to renew the tribunals in a three-paragraph White House statement. The administration said he was not embracing the Bush-era system because it would be so significantly changed.

However, his action was almost instantly denounced by a host of liberal-leaning groups that championed his presidential campaign last year.

"In one swift move, Obama both backtracks on a major campaign promise to change the way the United States fights terrorism and undermines the nation's core respect for the rule of law," said Amnesty International executive director Larry Cox.

"There is no such thing as 'due process light,'" said American Civil Liberties Union executive director Anthony D. Romero.

"As a constitutional lawyer, Obama must know that he can put lipstick on this pig — but it will always be a pig," said Zachary Katznelson, legal director of Reprieve, a London-based legal action charity that represents 33 Guantanamo detainees.

Obama's announcement was greeted more warmly on Capitol Hill, where he will need broad support to quickly push through tribunal changes. The White House hopes to do so before mid-September, when a new 120-day freeze the president put on the cases Friday runs out.

The Democratic chairman of the Senate Armed Services Committee, Carl Levin, D-Mich., called the changes "essential in order to address the serious deficiencies in existing procedures." Senate GOP Leader Mitch McConnell said the announcement was an "encouraging development."

"By taking this action, President Obama has reinforced that we are at war, and that the laws of war should apply to these prisoners," said Sen. Joe Lieberman, I-Conn.

The tribunal system was established after the military began taking detainees from the battlefields of Afghanistan in late 2001. But the process immediately and repeatedly was challenged by human rights and legal organizations for denying defendants rights they would be granted in most other courts.

As a senator, Obama voted for one version of the tribunal law that gave detainees additional rights, but then voted against the more limited 2006 legislation that ultimately became law. Friday's changes restore some of those rights, including:

_Restrictions on hearsay evidence that can be used in court against the detainees.

_A ban on all evidence obtained through cruel, inhuman or degrading treatment. This would include statements given from detainees who were subjected to waterboarding, a form of simulated drowning, although a U.S. official said no evidence of that kind had been allowed anyway.

_Giving detainees greater leeway in choosing their own military counsel.

_Protecting detainees who refuse to testify from legal sanctions or other court prejudices.

The latest delay, however, means Obama could face an uncomfortable choice as the clock runs out on his self-imposed January 2010 deadline to close Guantanamo.

His administration will have only four months to finish the nine trials before then, or risk moving the cases to the United States if they are still under way. If that happens, the detainees would be given even greater legal rights than they have at Guantanamo — and more than Obama wants to give.

Asking Congress to change the 2006 commissions law could create longer delays. Lawmakers, leery that the detainees could be brought to the U.S., already have held up funding for closing the prison until the White House outlines details of how it would happen.

Obama could roll back the January 2010 deadline, which he imposed on his second day in office. That could throw in doubt his campaign promise to shut down the prison and, at the least, highlight his struggle to reverse Bush-era national security policies that damaged America's image worldwide and stoked recruitment among insurgents.

Clive Stafford Smith, who represents several current and former detainees, was surprised that the Obama administration plans to restart the trials at Guantanamo instead of elsewhere. "There is zero chance that the military commissions could be over by January, so that cannot possibly be the plan," he said.

Navy Lt. Richard Federico, who represents two Guantanamo detainees charged before the military commissions, including alleged 9/11 plotter Ramzi bin al Shibh, also doubted cases could be completed by January. Litigation over the legality of the new rules "will certainly incur additional delay," Federico told The Associated Press.